Hydrogen reacts with chlorine to form hydrogen chloride. In this reaction, 679 kJ/mol is supplied to break bonds in the reactants. Forming bonds in the products releases 862 kJ/mol.
Which statement follows from these energy transfers?
The reaction is endothermic because forming bonds stores the released energy in the products
The reaction is exothermic because breaking the reactant bonds releases more energy than making the product bonds
The reaction is exothermic because making the product bonds releases more energy than breaking the reactant bonds takes in
The reaction is endothermic because supplying energy to break bonds means that the reaction takes energy in overall
85 exam-style questions on AQA GCSE Chemistry 5.1 Exothermic and endothermic reactions, covering 5.1.1 Energy transfer during exothermic and endothermic reactions, 5.1.2 Reaction profiles, and 5.1.3 The energy change of reactions. Each one has a worked solution and a mark scheme showing where the marks go.